Mounting for picture-projecting lights



Ffib. 9 C. F. JENKINS MOUNTING FOR PICTURE PROJECTING LIGHTS.

Filed July 18, 1918 E a f- F wuww J,

\fl/ fl Svwemtoz Patented Feb. 26, 1924.

STATES MOUNTING FOR IICTURE-PROJECTING LIGHTS.

Application filed July 18, 1918. Serial No. 2 55,43 1.

To all whom it may concern:

Be it known that I, CHARLES FRANCIS JENKINS, a citizen of the United States, and resident of Washington, in the District of 5 Columbia, have invented certain new and useful Improvement in Mountings for Picture-Projecting Lights, of which the following is a specification, reference being had therein to the accompanying drawing.

In the motion picture art it is now common to use for illumination incandescent electric lamps of high candle power, the light being produced by coiled filament having short segments extending back and forth 33 in a plane. Such lamps are obtainable commercially, and as made they are provided with the usual large screw threads so that they can be screwed into a standard socket. If the light from such a lamp is to pass through a lens, the latter should obviously be parallel to the 'plane of the incandescent filaments and should have its optical axis perpendicular to that plane at its middle point or themiddle point of the illuminating area.

In motion picture machinesv this axis should pass approximately through the middle of the exposure opening, and hence the lamp should be vertically adjustable, for

$0 properly framing the icture, while the illuminating filament is a ways in the proper plane whatever its adjustments. This is usually a matter of some difliculty, involving the adjustment of many parts. The

general objects of this invention are to provide for quickly adjusting a commonlamp while kee ing its filament in a single plane, and also or putting the lamp into the lightmg circuit, or removing it therefrom, almost 60 instantly.

In the accompanying drawings,

Figure 1 is a side elevation of a lamp arranged in accordance with this invention, some parts of the lamp-house and lamp sup- N port being shown in section.

Figure 2 is a plan view of a portion of the same devices the lamp itself beingmmitted.

In these views, A represents an insulating plate sliding in ways A in an ordinary to lam -house, and B a non-threaded, conducting amp socket sup orted from the plate by a conducting bar l) represents a high power electric lamp of the incandescent type, having the usual socket-fitting threads at E and a terminal in the middle of its end face. Against this terminal normally presses a strong conducting spring F fixed to the plate A and adapted to follow the lamp through a very considerable vertical distance as the lamp is varied in height. The socket is usuall of spring metal and is longitudinally divi ed along one side and provided with normally separated, outwardly projecting lugs G through which passes a manually operated bolt H by which the lugs may be drawn together causing the socket to grip the lamp.

The conducting bar C and the spring F are in electrical connection with springs or terminals I, I, respectively, carried below the plate and so arranged that slidin the plate forward in its ways pushes the am terminal connections over the inclined en s or end portions of the springs I, I, thus putting the lamp into the illuminatin oir- 75 cuit by the mere act of sliding it to position.

The bolt H being so far loosened that the threaded portion of a lamp may slide directly into the socket, a lamp with its filament in the proper plane is placed therein and pressed down, the spring F yieldin until the light beam passes properly throng the exposure aperture, and then the lamp is clamped by tightening the bolt H. Slightly loosening the bolt allows the spring, or the hand, or both, to raise the lamp if it has been pushed down too far.

It may be noted that the adjustment is quicker and easier than adjusting by rotation a lamp which can be so adjusted, that is a lamp which lacks the large plane illuminating area.

' Obviously the exact construction need not be followed.

What I claim is 1. The combination with supporting members provided with ways. of an insulating plate sliding in said ways, a compressing lamp socket having an internally smooth cylindrical surface, supported from the 100 .plate and provided with a terminal throu h which circuit may be made throu h t e socket as the plate slides and broken y opposite sliding.

2. The combination with a supporting structure provided with ways, of aninsulating plate slidably mounted in said ways and and a yielding contact member arranged to bearing a conducting lamp sooket'provided make contact with the central terminal of a with a terminal and adapted to hold an axlamp in said socket and maintain such con- 10 ially sliding lamp, a conductor mounted tact when the lamp is vertically adjusted.

6 alongside the path of said terminal in posi- In testimony whereof I hereunto afiix my tion to make and break contact therewith as signature. the plate slides back and forth in its ways, CHARLES FRANCIS JENKINS. 

